The invention relates to an air ducting system for cooling air in an air duct in a front end of a motor vehicle, which duct is arranged in front of a capsule surrounding an engine compartment in the direction of travel of the motor vehicle and has an essentially vertically positioned air inlet opening at a forward front end wall and an essentially horizontally positioned air outlet opening at an underside of the front end.
An air ducting system of this kind is known from AT-PS 385 245 B. In this known air ducting system, after flowing through a radiator the cooling air strikes the almost vertical rear wall, acting as deflection plate, of the air duct, with the result that it is forced to execute a sharp, almost right-angled deflection. These unfavorable flow conditions reduce the rate of flow of the cooling air and hence the possible cooling capacity.
An object on which the invention is based is to design an air ducting system of the type mentioned at the outset in such a way that higher cooling capacities are made possible by better flow conditions of the cooling air and by an increase in the cooling surface flowed over by the cooling air.
This object is achieved in an air ducting system of the type referred to above, wherein a plurality of aerodynamically shaped guide vanes divide the air duct into a plurality of subducts, said guide vanes being arranged in the air duct to extend as far as the air outlet opening at the underside of the front end, and wherein the guide vanes are of hollow design and are flowed through by a cooling medium transversely to the direction of flow of the cooling air.
In the air ducting system according to the invention, the cooling air is guided constantly by the guide vanes in a plurality of subducts without sharp deflection, with the result that, with other conditions the same, a lower-loss flow occurs which makes possible a higher rate of flow of cooling air and hence a greater cooling capacity. In addition, a considerable increase in the cooling surface flowed over by the cooling air and hence a further improvement of the cooling capacity is achieved, it furthermore being possible to save on the space for a separate radiator or without the need for additional space, to provide an additional radiator, such as a condenser or an oil cooler.
It is already known from MTZ October 1958, pages 347 and 348 to arrange air baffles in a pipe bend behind the radiator of a vehicle cooling system, said air baffles reducing the loss coefficients of the cooling air flow. An armored vehicle is furthermore known from U.S. Pat. No. 2,439,775, in which annular air guide vanes are arranged which serve to deflect cooling air between an air inlet and a fan and simultaneously represent heat exchangers for oil flowing through their interior.
The use of the lateral walls of the air duct as radiator tanks in accordance with certain preferred embodiments represents a considerable cost and space saving. In addition, as part of the capsule, they contribute to the sound insulation of the engine compartment.
In space-saving manner, the design of the air ducting system in certain preferred embodiments includes the capsule wall in the formation of the air duct with its advantages in terms of flow.
The air ducting system according to certain preferred embodiments improves the flow conditions over the entire path between the radiator, situated near to the air inlet opening, and the air outlet opening. There is the possibility, by appropriate design of the cooling ribs in the radiator, to direct the incoming cooling air onto the guide vanes already at this point.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.